实体尝试更新不正确的 table / IEntityChangeTracker 问题的多个实例

Question

这可能是个愚蠢的问题，但我还是要问。

一些事实。

根据我的参考，我使用实体 6.0.0.0。
我遇到了天蓝色的 sql 分贝。
该项目基于 mvc 默认模板 thingo。

所以我试图通过以下代码添加到 table。请注意，每次只尝试了 1 条路径，而不是同时尝试全部 3 条路径或组合。

public User(UserModel userModel)
{
    using (var db = new SqlDogContext())
    {
        // Path 1 this seem like there is a better way but throws an exception anyways
        var sillyModel = new UserModel() { Id = userModel.Id };

        db.UserLibarys.Add(new UserLib {User = sillyModel, Libary = RssLibObject});
        db.SaveChanges();

        db.UserLibarys.Add(new UserLib {User = sillyModel, Libary = KodiLibObject});
        db.SaveChanges();

        db.UserLibarys.Add(new UserLib {User = sillyModel, Libary = SoundCloudLibObject });
        db.SaveChanges();

        db.UserLibarys.Add(new UserLib {User = sillyModel, Libary = SpotifyBridgeObject });
        db.SaveChanges();

        // Path 2 I guess this would be ok
        var sillyModel = new UserModel() { Id = userModel.Id };
        db.UserLibarys.Add(new UserLib { User = sillyModel, Libary = RssLibObject });
        db.UserLibarys.Add(new UserLib { User = sillyModel, Libary = KodiLibObject });
        db.UserLibarys.Add(new UserLib { User = sillyModel, Libary = SoundCloudLibObject });
        db.UserLibarys.Add(new UserLib { User = sillyModel, Libary = SpotifyBridgeObject });
        db.SaveChanges();

        // Path 3 - What i want to use..
        db.UserLibarys.Add(new UserLib { User = userModel, Libary = RssLibObject });
        db.UserLibarys.Add(new UserLib { User = userModel, Libary = KodiLibObject });
        db.UserLibarys.Add(new UserLib { User = userModel, Libary = SoundCloudLibObject });
        db.UserLibarys.Add(new UserLib { User = userModel, Libary = SpotifyBridgeObject });
        db.SaveChanges();

    }
}

路径 1 出现以下异常。

    {"Violation of PRIMARY KEY constraint 'PK_dbo.UserModels'. 
     Cannot insert duplicate key in object 'dbo.UserModels'. 
     The duplicate key value is (009d1c33-a3cf-49db-8243-ff8a447eff16).
     \r\nThe statement has been terminated."}

路径 2 出现以下异常。

    An exception of type 'System.Data.Entity.Validation.DbEntityValidationException' occurred in EntityFramework.dll but was not handled in user code

使用我在 Whosebug 某处找到的这个。

try
{
    // Your code...
    // Could also be before try if you know the exception occurs in SaveChanges

    db.SaveChanges();
}
catch (DbEntityValidationException e)
{
    foreach (var eve in e.EntityValidationErrors)
    {
        Console.WriteLine("Entity of type \"{0}\" in state \"{1}\" has the following validation errors:",
            eve.Entry.Entity.GetType().Name, eve.Entry.State);
        foreach (var ve in eve.ValidationErrors)
        {
            Console.WriteLine("- Property: \"{0}\", Error: \"{1}\"",
                ve.PropertyName, ve.ErrorMessage);
        }
    }
    throw;
}

我收到以下消息

The User field is required.

这对我来说意义不大，因为在我看来，我正在提供它。

路径 3 出现以下异常。

    Additional information: An entity object cannot be referenced by multiple instances of IEntityChangeTracker.

这让我感到困惑，因为它看起来更新错误 table。这是我的模特

public class UserLib
{
    [Key]
    public int LibId { get; set; }

    public bool UserEnabled { get; set; }

    [Required]
    public virtual Lib Libary { get; set; }

    [Required]
    public virtual UserModel User { get; set; }
}

public class UserModel
{
    [Key, ForeignKey("ApplicationUser")]
    public string Id { get; set; }

    public virtual UserLib Libary { get; set; }
    public virtual ApplicationUser ApplicationUser { get; set; }
}

public class Lib
{
    public string Name { get; set; }
    public string Logo { get; set; }

    [Key]
    public int LibId { get; set; }

    public virtual UserLib UserLib { get; set; }
}

public class ApplicationUser : IdentityUser
{
    public virtual UserModel MyUserModel { get; set; }
    // plus some other stuff in here that seems non relavent
}

这是创建用户模型的地方

using (var db = new SqlDogContext())
{ 
     db.UserModels.Add(
        new UserModel()
        {
            Id = currentId
        }
    );

    db.SaveChanges();

    query = from b in db.UserModels
            where b.Id == currentId
            select b;
}


_CurrentUser = new User(query.First());

最终目标是一个用户对应一个用户模型许多用户库的一个用户模型并让 UserLibaries 拥有库数据库的外键。

所以我可能犯了一个新手错误，但是有人能看到我的问题吗:)。

Answer 1

您正在尝试设置主键：var sillyModel = new UserModel() { Id = userModel.Id };然后多次存储它，这是你做不到的。让 entity framework 设置主键。另请注意，您不必在每次操作后继续调用 SaveChanges()。您可以执行所有插入操作，然后调用一次。

实体尝试更新不正确的 table / IEntityChangeTracker 问题的多个实例

Entity Attempting to update incorrect table / multiple instances of IEntityChangeTracker issue

c#

sql

asp.net-mvc

entity

entity-framework